Surface Finish Issues On 12x36 (long Post) + Kb Electronics Vfd Install

[Greebles]

These are my preferred inserts for aluminum.

http://latheinserts.com/CCGT-3251-INSERT-FOR-ALUMINUM-1-03-000329.htm

These are GREAT for aluminum!

 

[KevinMaiorka]

"I have a suspicion based on personal experience....humor me? Please post a pix of the tool post and compound ."

To whom & what are you referring?

Jerry in Delaware

I believe he is referring to you and a pic of your tool post and compound slide as well. I'm pretty sure he is thinking that there might be a rigidity issue there. I don't personally see how a belt issue can cause a poor finish when your headstock is running true.

Sent from my LGLS991 using Tapatalk

 

[jbolt]

Have you checked if the head stock to bed bolts are tight?

 

[juiceclone]

I believe he is referring to you and a pic of your tool post and compound slide as well. I'm pretty sure he is thinking that there might be a rigidity issue there. I don't personally see how a belt issue can cause a poor finish when your headstock is running true.

Yes, that was on my mind.. I had a finish similar to his when I installed a Chinese QC tool post. Found the bottom surface was not "flat" and when tightened down the actual load bearing area was right around the bolt. (imparting a microscopic rocking) Just ground off tiny amount of metal all around the bottom surface almost out to the edge, and it cured it immediately.

 

[Muskt]

A couple of answers.

I have not checked the bolts, yet--very good thought--I will do that tomorrow.

About the QCTP--another excellent idea--I experienced that exact problem with a Phase II on my 9x20 several years ago and even wrote about it on the 9x20 forum. I used nearly the same procedure for the repair--I turned it in the 4-jaw instead of grinding.

Since is is past 10PM now, I'll check both of those things tomorrow, & report back.

Thanks,
Jerry in Delaware

 

[Muskt]

On with the story.

This morning, I went to the shop & did some inspections.

1. Headstock bolts-----All tight.
2. Compound top surface---Not pristine, but not terrible, either-------Wrapped 600grit wet or dry around a large ceramic stone & polished (gently) the top surface.
3. QCTP bottom surface------really difficult to tell, so I placed a sheet of 600 wet or dry on my granite plate & a few drops of oil and gently rubbed the QCTP around (letting gravity do the downward pushing)---Wiped it frequently & continued till the bottom was about 90% shiny.

Tried another test cut on same material at the same speed/feed & with the same tool----NO CHANGE!
Repeated the test cut with the compound and the cross slide locked----NO CHANGE!

Next, I just let the machine run without the feed engaged---small vibrations evident (not huge, just a bit of vibration).
1. Checked the floor pads and made a tiny adjustment to one of them---very small improvement in the vibration.
2. Fussed with the floor pads till the minimum vibrations observed.
3. Removed the chuck & repeated the run listed above---still vibrating about the same.
4. Removed the drive belt & repeated---vibration gone. HMMMMM!!!

OK, I still haven't made a video. I am just about out of ideas.

Let me restate that the surface finish I am observing is not gross, or terrible. It is just not what I think it should be.
One more time---I am not terribly upset, PO'd, or any number of negative things--I just am hoping to get it all squared away.

I think I will just stop for a while & cut the grass.

Jerry in Delaware

 

[KevinMaiorka]

Jerry, thanks for letting us all know how it is going and I am interested to find out what it is that is causing your issues.

Hoping for a simple fix but I am personally out of ideas.

Sent from my LGLS991 using Tapatalk

 

[francist]

That make for a great life axiom -- "Sometimes you should just stop and cut the grass"


-frank

 

[Muskt]

Well, I'm not sure if they will be of any benefit; however, here are three short videos of the 12x36. Attempting to create these has given me an increased appreciation of what guys like Abom & K. Fenner & others do on a regular basis.

Just for reference: spindle speed = 700. Feed rate = 0.002. DOC = 0.005. Insert = TCGT. Material = 6061 @ approx 11/16 diameter.

Be Gentle, now.

Jerry In Delaware

 

[Muskt]

I guess (in retrospect) I should have left the camera run after the cut was finished in the 2nd video. It looks exactly like it does before the cut started.

Jerry in Delaware